I don't think this approach is bad. The issues are asking if the project will accept contributions to add support, not demanding the maintainers add it.

Let's assume that they didn't have these container restrictions and could just use an ordinary docker-compose.yml, they'd still probably want to use something like OAuth2.0 for centralised login which a lot of these services won't have.

What would be better, making a massive PR to add support for it, or opening an issue to discuss it with the maintainer first?